Three Main Causes of Quality Issues
Market feedback and industry analysis highlight the following primary reasons for frequent failures in diesel generator sets:
- Manufacturers using standby engines as prime engines
- Use of copper-clad aluminum rotors alternator
- Use of domestically assembled or counterfeit engines
Detailed Explanation of Causes
1. Difference Between Standby and Prime Engines
In diesel generator sets, engines are classified as either standby engines or prime engines based on their intended purpose. A standby engine is designed for temporary power supply, such as during outages, and is suited for short-term, infrequent use. Conversely, a prime engine is engineered for continuous operation, capable of handling extended periods of high-load performance.
To reduce costs, some manufacturers market standby engines as prime engines. While these engines may share the same model number, their internal components, durability, and specifications (SO numbers) often differ. When a standby engine is used in a continuous, high-load application, it overheats and wears out quickly, leading to premature breakdowns. This explains why many customers face generator set failures just after the warranty period.
2. Motor Rotor Material Selection
The motor is a vital part of a diesel generator set, and the rotor material significantly affects power efficiency and lifespan. Traditionally, rotors are made from pure copper due to its superior conductivity and heat resistance. However, because copper is costly, some manufacturers opt for copper-clad aluminum rotors—aluminum cores coated with a thin copper layer—to cut expenses.
Although copper-clad aluminum rotors reduce production costs, they offer lower conductivity and poorer heat dissipation compared to pure copper. Under high-load conditions, these rotors overheat, decreasing motor efficiency and raising the risk of failure. This choice of material undermines the reliability and durability of the diesel generator set.
3. Engine Sourcing Issues
Certain diesel generator sets in the market rely on domestically assembled engines or counterfeit engines. Domestically assembled engines often lack rigorous quality control, featuring subpar materials and craftsmanship. Counterfeit engines, meanwhile, are imitation products that mimic reputable brands but fail to meet quality standards.
These engines typically function adequately during the warranty period but deteriorate afterward, resulting in a surge of failures post-warranty. Customers find it challenging to differentiate genuine products from counterfeit motors based solely on appearance, increasing the risk of acquiring inferior equipment.
Impact on Customers
Purchasing Advice
To steer clear of substandard diesel generator sets, customers should follow these recommendations during the buying process:
- Verify the Engine’s Usage Rating
- Request detailed specifications and proof from the manufacturer to distinguish between standby engines and prime engines.
- Confirm the engine’s SO number aligns with your usage needs.
- Inspect the Motor Rotor Material
- Ask about the rotor material and favor pure copper rotors over copper-clad aluminum rotors.
- If feasible, request disassembly diagrams or inspections to verify the material.
- Confirm the Engine’s Origin
- Choose diesel generator sets from trusted brands and avoid suspiciously cheap options from unknown suppliers.
- Demand original certifications and warranty details to protect against counterfeit engines.
- Consider Extending the Warranty Period
- Negotiate a longer warranty with the manufacturer to safeguard against potential quality issues.
- Ensure after-sales support is available for prompt repairs if failures occur.
Conclusion
Continue preparing your specification
Use these related resources to prepare your requirements. Final equipment selection depends on the confirmed load, duty and installation conditions.
Industrial: duty and load profile, voltage / frequency / phase, installation conditions and control interfaces.